Did you adjust your child's bedtime when they stopped napping?

E just turned 4 and doesn't nap most days. He lays down, but only sleeps about a third of the time. We've been having a lot of behavioral problems in the evenings, not listening, purposely defying us, shouting, acting crazy. After exhausting other options I threatened him with going to bed early tonight and had to follow through, resulting in him going to bed about 45 min early. He was asleep in 5 minutes and hasn't moved. I'm thinking his bedtime might need to be adjusted now that he doesn't nap?